PeterW

Depends if you want to get into Darcy-Weisbach calculations here, and the turbulent flow characteristics of small pipes ..?? As a rule of thumb (which John Hearfield explains well) then the following are pretty good for flow rates with little noise pipes 10 mm 15 mm 22 mm 28 mm 35 mm 42 mm 54 mm 1.5 m/sec 0.08 0.22 0.45 0.82 1.3 1.9 3.1 2.0 m/sec 0.1 0.3 0.6 1.1 1.7 2.5 4.2 That gives your 10mm pipe a max flow of between 5.4 and 6 l/min - you couldn’t put 5m/s through a 10mm pipe without significant noise and pressure loss.

I’d expect those actuators are spring closed so take one off and see if the flow stops. If not you may have to remove an actuator one at a time. All your circles are spot on ..!! Inhibitor... quickest way is whilst it’s all isolated, close the top and bottom drain valve and then remove the white air vent screw. Get one of these from Screwfix in a standard skeleton gun, and insert it into the valve. You can now carefully open the bottom valve and squeeze the cartridge into the system and it will displace the water from the loops as the inhibitor is added. When it’s done, close the bottom valve, remove the inhibitor and put the air valve back in. Open the manifold isolator valves. Let the system run for 10-20 mins to circulate the inhibitor and then top the system pressure up to 2bar. Run again, and bleed the air from the vent. You may need to do this 2 or 3 times, and repressurise to 2bar each time.

They will be a standard bearing on the fan - wonder if it’s out of balance ..? Plenty of companies out there who do motor rewinds and repairs - not sure where you are in the UK ..? Just do a search for Motor Rewinds. If you’re East Mids then MER do a fan repair service - may be worth a call.

Sounds like water has got into the bearings - it happens. They then freeze up and only thaw when they get some movement. If you can access the fan - shouldn’t be too difficult. - and get the unit off you may be able to strip it down and clean it up. Electrical contact cleaner or brake cleaner is good for getting water and crud out of bearings and that sort of thing. Once you’ve got it stripped and cleaned, a good coating of copper grease should keep it moving, repacking bearings with ordinary bearing grease will probably do if you don’t have any copper grease (Motor Factors sell it in small tubes) but don’t use WD40 as it doesn’t last long enough.

Would finish it nicely and be neat.

That’s too hot for UFH ! Turn it down ..!! If it is a new build then it will have to have met the 0.11 uValue target. Ask for the build up of the floor - also have you got your EPC/SAP certificate for the house ..? I would also wonder at those temperatures if the boiler is getting into condensing mode so will be more inefficient and use more gas. I would be looking at reducing the flow temperature (both boiler and UFH) and adding a couple of hours to the run times. Also with gas you have no variable cost so also look at running it for 3 periods in the day - I can’t work out if you’re saying that it’s on permanent from 7am-9pm..? The other issue will be the combi - how much hot water are you using ..? And did your old house use a tank or a combi boiler ..?

Needs some sort of threshold but in something hard wearing so you don’t need to constantly paint it. Have you got any LVT left over ..?? you could get a piece of hardwood such as sapele which is quite “solid” and bond it / screw to the concrete and then have LVT bonded onto that - would look like a small internal step and low enough you won’t trip over it.

See my comment on your other post. Go with the Architect on this one.

PIR. Every day of the week. The hybrid stuff is a thinly insulated turkey roasting bag of suspect credentials which when detailed correctly stops your convection losses but is questionable on anything else.

32mm is only needed for high flow high use properties where 3 showers are required concurrently. 25mm at 2.5bar is more than adequate 15mm off a 22mm main is very traditional and requires point of use isolation and it’s better to use manifold isolation if possible plus 10mm to basins as it reduces cold leg and increases efficiency. 8l/min is on the low side of acceptable for flow - most mains flow shower heads are designed for 12 l/min which is what consumers expect these days.

I use Copley’s calculator as it allows you to change the values via the graph https://www.copely.com/tools/flow-rate-calculator/

Nothing to do with pipe size, this is because he takes his cold feed off before the control block and not from the balanced cold port. This will affect balance as you could have 6bar cold and 3bar hot. It’s really bad practice ..! You have put a restriction where one is not required and 99.9% of tanks come with 22mm as a minimum in and out. You will struggle to get full flow into the manifold at 15mm, even with decent pressure. Also, look at his layouts and the tank and manifold are miles from the cold supply - classic under the kitchen sink and this is a new build so why not the utility and run everything from there ..?? Pressure drop may be 0.5bar (if you’re lucky) however he’s got it mixed with a full mains 15mm supply. So off balancing will mean your 12 l/min cold will swamp your 7 l/min hot and you won’t be able to balance it correctly. 12mm MLP has a bore of 10.2mm, and at 3bar and 10m length my calculator shows a flow of 4.6l/min hot and 15mm cold at 4.5bar giving 12.6l/min. That is a huge discrepancy. At 3bar even 15mm is only giving you 8.8l/min so this is why showers need decent sizing. Nope neither would I and he discounts ASHP as expensive imported tech which it isn’t.. and I wouldn’t call Vaillant reliable unless you install all their kit and controls, as they don’t play nicely with other systems ..!! There are better products.

Thats a really poor schematic, and will cause a number of issues and has some errors. The UFH (which he states they aren’t using) will cause short cycling in the boiler as there is no buffer; the cold feeds to taps will be unbalanced so it will cause issues with any mixer taps or showers as should be off the control block; WC feeds are not shown (but should be where all cold is shown); the hot water will be throttled as there is a 22mm supply but a 15mm outlet (..??!), and 12mm to showers is far too small. He also off balances the showers using 12mm hot and 15mm cold. Also, his heating schematic shows two bedrooms without radiators - this is the issue with PHPP in that he only wants a small heat input (~5kW from a quick add up) yet he discounts UFH. The better choice for this would have been UFH with a 8kW ASHP which would be more cost effective and simpler to install.

Part G of the Building Regulations require you to limit the temperature of any hot water at a bath to 48°C so you will need to fit a thermostatic mixer or use a TMV at any bath outlet. This is one I have seen checked by a BCO too ..!

Good news is you’ve got drain valves on the manifold so you can flush the loops. It should have inhibitor in the system but if it’s 10 years old then it should be replaced anyway. Is this a gas boiler system too.?? You'll need a couple of lengths of hosepipe and some jubilee clips (don’t expect the hoses to stay on under pressure ..!) and connect the mains water to the supply and the drain off to the return. Isolate the manifold using the valves to the right of the pump so you’re only flushing the circuits. Mark all the heads and remove them - you want to manually flush the loops - and then open the flow and return isolators and push the first pin down. Open the valves on the hose ends and this should show flow through the valve and first circuit and any crap should come out. Run it for a minute - having an assistant to watch the rubbish coming out is worth it. When it is running clean then push the next pin and release the first. This will flush the whole lot and also push the air out - when you’ve done, turn off the isolators and the water, and then open the pump isolators. You may find you need to bleed the manifold after it runs for a while - that’s the white bleed valve on the top left. One thing I would note is the pressure is low - is this run from a boiler and is there an expansion tank on the system ..? When was it checked last ..?

the only way you will find this is physical investigation. You’ll need to access the inside of the chimney and get a camera in there and then work out where the water is getting in. As a minimum I expect those pots and the top flaunching needs removing and redoing, the lead work may also be suspect so it will require a good amount of investigation to find the true source of the leaks.

Not been edited so would have to go with the latter ...

@Russell griffiths why not use Quinetic switches if it’s just for lights as you can put them wherever you want without cables.

25mm won’t bend as well so make sure you have big radius bends in the duct. I’d run 25mm just for peace of mind.

Do not use a spring that close to the joint - you will stress the joint and make it weep. I would dig it out and move it properly.

Thanks - makes sense if it’s extensions etc.

Not at all - it stops steam bubbles forming in the water on the elements which is what makes the noise as they warm up. Sometimes called a wetting agent, or water wetter too..!!

@zoothorn please keep using the CH, and don’t go back to the heaters as your electricity bill will increase not decrease !! A fan heater is a resistance heater, and for each kW of electric you put in, you get nearly a kW of heat out. A heat pump uses the electricity to pull heat from the air, and for every kW of electric you put in, you get between 2 and 4 kW of heat out ( the CoP or coefficient of performance) Heat pumps are much more efficient and even if they only get a CoP of 2, it is twice as effective and half the cost of the same heat input from your heaters. Now it is working properly, you need to get it running properly and see what improvement you see.

Any reason not to just use the concrete as the finished floor and get rid of the screed..?

You can’t - Sunamp is providing potable water not heating and there is no way to make it do both. Depends on the Sunamp but if it’s and electric only then there is no way to heat them with a water circuit and an ASHP doesn’t get hot enough to phase change the PCM (needs 59°C) Yes - and they aren’t expensive. Do you have space for a buffer tank also where the UFH manifold is ..? I would get a 3-5kW ASHP and connect it via a buffer and run off peak. Assuming you have PV diversion then also get a buffer that can take an immersion and connect this as second dump load to the PV. Also gives you redundancy in the event of failure of the ASHP.